Full definition
Term used in process industries (refinery, petrochemical, chemical) for the planned major shutdown of a unit or entire plant for inspection, repair and modification. Unlike generic shutdowns, the turnaround involves regulatory obligations (API 510 for vessels, API 570 for piping) and inspections by certified bodies. Planning starts 18-24 months in advance; executors combine in-house maintenance and specialized contractors. Typical cost: millions of USD. Delayed startup costs hundreds of thousands USD/day in lost production.